/* Copyright  (c) 2002 Graz University of Technology. All rights reserved.
 *
 * Redistribution and use in  source and binary forms, with or without 
 * modification, are permitted  provided that the following conditions are met:
 *
 * 1. Redistributions of  source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in  binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  
 * 3. The end-user documentation included with the redistribution, if any, must
 *    include the following acknowledgment:
 * 
 *    "This product includes software developed by IAIK of Graz University of
 *     Technology."
 * 
 *    Alternately, this acknowledgment may appear in the software itself, if 
 *    and wherever such third-party acknowledgments normally appear.
 *  
 * 4. The names "Graz University of Technology" and "IAIK of Graz University of
 *    Technology" must not be used to endorse or promote products derived from 
 *    this software without prior written permission.
 *  
 * 5. Products derived from this software may not be called 
 *    "IAIK PKCS Wrapper", nor may "IAIK" appear in their name, without prior 
 *    written permission of Graz University of Technology.
 *  
 *  THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 *  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE LICENSOR BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 *  OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 *  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 *  OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY  OF SUCH DAMAGE.
 */

package iaik.pkcs.pkcs11.objects;

import iaik.pkcs.pkcs11.Session;
import iaik.pkcs.pkcs11.TokenException;
import iaik.pkcs.pkcs11.wrapper.Constants;



/**
 * Objects of this class represent a data object as specified by PKCS#11
 * v2.11.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (application_ <> null)
 *             and (objectID_ <> null)
 *             and (value_ <> null)
 */
public class Data extends Storage {

  /**
   * The application description attribute of this data object.
   */
  protected CharArrayAttribute application_;

  /**
   * The object ID attribute of this data object (DER-encoded).
   */
  protected ByteArrayAttribute objectID_;

  /**
   * The value attribute of this data object.
   */
  protected ByteArrayAttribute value_;

  /**
   * Deafult Constructor.
   *
   * @preconditions
   * @postconditions
   */
  public Data() {
    super();
    objectClass_.setLongValue(ObjectClass.DATA);
  }

  /**
   * Called by getInstance to create an instance of a PKCS#11 data object.
   *
   * @param session The session to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @param objectHandle The object handle as given from the PKCS#111 module.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions
   */
  protected Data(Session session, long objectHandle)
      throws TokenException
  {
    super(session, objectHandle);
    objectClass_.setLongValue(ObjectClass.DATA);
  }

  /**
   * Put all attributes of the given object into the attributes table of this
   * object. This method is only static to be able to access invoke the
   * implementation of this method for each class separately (see use in
   * clone()).
   *
   * @param object The object to handle.
   * @preconditions (object <> null)
   * @postconditions
   */
  protected static void putAttributesInTable(Data object) {
    if (object == null) {
      throw new NullPointerException("Argument \"object\" must not be null.");
    }

    object.attributeTable_.put(Attribute.APPLICATION, object.application_);
    object.attributeTable_.put(Attribute.OBJECT_ID, object.objectID_);
    object.attributeTable_.put(Attribute.VALUE, object.value_);
  }

  /**
   * Allocates the attribute objects for this class and adds them to the
   * attribute table.
   *
   * @preconditions
   * @postconditions
   */
  protected void allocateAttributes() {
    super.allocateAttributes();

    application_ = new CharArrayAttribute(Attribute.APPLICATION);
    objectID_ = new ByteArrayAttribute(Attribute.OBJECT_ID);
    value_ = new ByteArrayAttribute(Attribute.VALUE);

    putAttributesInTable(this);
  }

  /**
   * The getInstance method of the Object class uses this method to
   * create an instance of a PKCS#11 data object.
   *
   * @param session The session to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @param objectHandle The object handle as given from the PKCS#111 module.
   * @return The object representing the PKCS#11 object.
   *         The returned object can be casted to the
   *         according sub-class.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions (result <> null) 
   */
  public static Object getInstance(Session session, long objectHandle)
      throws TokenException
  {
    return new Data(session, objectHandle) ;
  }

  /**
   * Create a (deep) clone of this object.
   *
   * @return A clone of this object.
   * @preconditions
   * @postconditions (result <> null)
   *                 and (result instanceof Data)
   *                 and (result.equals(this))
   */
  public java.lang.Object clone() {
    Data clone = (Data) super.clone();

    clone.application_ = (CharArrayAttribute) this.application_.clone();
    clone.objectID_ = (ByteArrayAttribute) this.objectID_.clone();
    clone.value_ = (ByteArrayAttribute) this.value_.clone();

    putAttributesInTable(clone); // put all cloned attributes into the new table

    return clone ;
  }

  /**
   * Compares all member variables of this object with the other object.
   * Returns only true, if all are equal in both objects.
   *
   * @param otherObject The other object to compare to.
   * @return True, if other is an instance of this class and all member
   *         variables of both objects are equal. False, otherwise.
   * @preconditions
   * @postconditions
   */
  public boolean equals(java.lang.Object otherObject) {
    boolean equal = false;

    if (otherObject instanceof Data) {
      Data other = (Data) otherObject;
      equal = (this == other)
              || (super.equals(other)
                  && this.application_.equals(other.application_)
                  && this.objectID_.equals(other.objectID_)
                  && this.value_.equals(other.value_));
    }

    return equal ;
  }

  /**
   * Gets the application attribute of this data object.
   *
   * @return The application attribute.
   * @preconditions
   * @postconditions (result <> null)
   */
  public CharArrayAttribute getApplication() {
    return application_ ;
  }

  /**
   * Gets the object ID attribute of this data object.
   *
   * @return The object ID attribute.
   * @preconditions
   * @postconditions (result <> null)
   */
  public ByteArrayAttribute getObjectID() {
    return objectID_;
  }

  /**
   * Gets the value attribute of this data object.
   *
   * @return The value attribute.
   * @preconditions
   * @postconditions (result <> null)
   */
  public ByteArrayAttribute getValue() {
    return value_;
  }

  /**
   * The overriding of this method should ensure that the objects of this class
   * work correctly in a hashtable.
   *
   * @return The hash code of this object.
   * @preconditions
   * @postconditions
   */
  public int hashCode() {
    return application_.hashCode()
           ^ objectID_.hashCode()
           ^ value_.hashCode() ;
  }

  /**
   * Read the values of the attributes of this object from the token.
   *
   * @param session The session handle to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions
   */
  public void readAttributes(Session session)
      throws TokenException
  {
    super.readAttributes(session);

    Object.getAttributeValue(session, objectHandle_, application_);
    Object.getAttributeValue(session, objectHandle_, objectID_);
    Object.getAttributeValue(session, objectHandle_, value_);
  }
  
  /**
   * This method returns a string representation of the current object. The
   * output is only for debugging purposes and should not be used for other
   * purposes.
   *
   * @return A string presentation of this object for debugging output.
   * @preconditions
   * @postconditions (result <> null)
   */
  public String toString() {
    StringBuffer buffer = new StringBuffer(128);

    buffer.append(super.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Application: ");
    buffer.append(application_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Object ID (DER, hex): ");
    buffer.append(objectID_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Value (hex): ");
    buffer.append(value_.toString());

    return buffer.toString() ;
  }

}
